Mechanism of Water Splitting Catalysed by Co-intercalated Birnessite Studied by SCAN MetaGGA

Designing cheap, efficient and robust catalysts facilitating the splitting of water into oxygen and hydrogen is a worthwhile goal for conversion of solar energy into chemical energy, which helps eliminate the fossil fuel dependence of mankind. Inspired by the outstanding water-splitting ability of a manganese-bearing biological system, photo-system II (PS-II), manganese-containing compounds has been one of the research focuses for oxygen evolution reaction (OER) catalysts. Recently, a ubiquitous manganese oxide mineral, birnessite, has shown impressive performance for OER when intercalated with Co atoms, due to its special 2D-layered structure¹. To understand the mechanism of activity of Co intercalated birnessite for OER, we propose a first-principles study using the newly developed SCAN functional² to clarify possible effects contributing to the adsorption energies and overpotentials. These contributions include confinement effect, water layer effect, and Co concentration effect.


¹A. C. Thenuwara, D. R. Strongin, ACS Catalysis 6, 7739 (2016).
²J. Sun, A. Ruzsinszky, J. P. Perdew, Physical Review Letters 115, 036402 (2015).